Elmo ISP manual Dynamic contouring of continuous and peak current limits

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Ip - Iop

Tp = 2.2ln ----------

Ip - Ic

Ic - Amplifier continuous current rating.

Ip - Peak demanded (not amplifier Ip)

Iop - Actual operating current before the peak demand.

Example:

A motor is driven by an ISP-15/65 amplifier at constant speed and constant current of 5A. What is the maximum possible duration of a 20A peak ?

20 - 5

Tp = 2.2ln -------- = 2.42 seconds

20 - 15

4.5.2Dynamic contouring of continuous and peak current limits

Most of the servo motors have reduced continuous current limits at high speeds (Fig. 4.2). This phenomenon is due to commutation limits and iron looses which become significantly high as speed increases and this leads to reduction of the continuous current limit. The ISP amplifiers have the features which enable the user to define the current limit envelope as closely as possible to the motor operating envelope defined by the motor manufacturer.

Velocity

Cont. zone

Interm. zone

Torque

Fig. 4.2:

Typical operating envelope of a brush servo motor

ISP - Rev 6/95

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Contents Rev 6/95 ISP Rev 6/95 ELMO-WARRANTY Performance Read chapters Table of Contents Balance adjustment Current limit adjustment Standard features DescriptionProtective functions Technical specifications Type DesignationOperation of the servo control Inputs Velocity mode Velocity control using armature voltage feedback Current modeCurrent loop Current limitsTime dependent peak current limit Dynamic contouring of continuous and peak current limits Operation of the shunt regulator Temperature protection Loss of velocity feedback signalProtective functions Short circuit protectionCurrent Command Monitor Input ISP Control Board Page Contact rating 0.5A, 200V, 10W Terminals of ISP Panel Version Mother Board terminals MBA-ISP/N Terminals for ISP mounted in 3U size ENC GNDContact rating 0.5A, 200V, 10W Page MBA ISP/3UE Installation procedures Mounting WiringAC power supply Load inductance2Vdcmin Vdc 0.9Vdcmax Wiring diagrams ISP GNDGround Do not groundAC ISP ISP Control Connections Tachogenerator Feedback ISP Control Connections Armature Voltage Feedback Start Up Procedures Disable by LowEnable by High ISP Control Board Converting the amplifier into current mode Selecting the reference signal gainSee .1 for calculation of other values Activating the loss of tacho protection velocity mode only For VtmLatch mode of the protective functions Velocity control using tachogenerator feedbackActivating the dynamic contouring of the current limits For ISP-X/65 For ISP-X/135IxR compensation Amplifier adjustment and diagnostics Balance adjustmentCurrent limit adjustment Adjusting the motor speed velocity mode only Adjustment of the IxR compensationResponse adjustment velocity mode only Typical velocity response waveforms ISP Rev 6/95 Tables and Summaries Adjusting trimmers LED diagnosticsAppendix a Response adjustment current loop Fig. A-1 Typical current response waveforms ISP Rev 6/95 Appendix B Current limits contour adjustment Velocity TorqueDynamic contouring with armature voltage feedback ISP Rev 6/95 SP1 TOP View SP1 Side View SP1 Side View SP2 TOP View SP2 Side View SP2 Side View SP3 TOP View SP3 Side View SP3 Side View SP4 TOP View SP4 Side View SP4 Side View ISP Rack Mounting 8T and 15T TOP View ISP Rack Mounting 3U/8T Side View 128.7 Front Panel for ISP 3U/8T ISP Rack Mounting 3U/15T -SIDE View ISP Rack Mounting 3U/15T Side View Front Panel for ISP 3U/15T ISP Rack Mounting 3U/12T and 3U/19T TOP View ISP Rack Mounting 3U/12T -SIDE View ISP Rack Mounting 3U/12T Side View Front Panel for ISP 3U/12T ISP Rack Mounting 3U/19T -SIDE View ISP Rack Mounting 3U/19T Side View Front Panel for ISP 3U/19T Enclosure Mechanical Outline List of Elmo Service Centers Europe